Platen, etc., for typewriting and like machines



C. T. DICKEY PLATEN ETC., FOR TYPEWRITING AND LIKE MACHINES July 16, 1935.

\ Filed Dec. 15, 1954 ATTORNEY Patented July 16, 1935 PLATEN, ETC., FOR TYPEWRITING AND LIKE MACHINES Charles '1. Dickey, Elizabeth, N. J., assignor t6 Rodic Rubber Corporation, Garwood, N. J., a corporation of Delaware Application December 15, 1934, Serial No. 757,616 15 Claims. (Cl. let-'14:!)

. My invention relates to platens, feed rollers and the like employed in typewriting and like machines.

One of the main objects of my invention, generally stated, is to provide an improved platen or feed roller which is more effective than those ordinarily employed and contributes more effectively to the production of clearly defined imprints.

Another object of my invention resides in the provision of a platen, having a highly eflicient contact surface that will more effectively withstand the impacts of the types thereon without marring such surface, and'will retain its life and useful properties for a longer period than the ordinary rubber covered platens now in use.

Still another object of my invention is to provide a platen which reduces to a substantial degree the noise produced on ordinary platens from the impacts or hammer blows of the types thereon.

A further object of my invention is to provide a platen which will materially aid in the production of clear and distinct carbon copies and is more efiicient for this purpose than similar grades of rubber covered platens heretofore used.

Another object of my invention is to provide a contact surface for platens, feed rollers and the like made of a composition comprising polymerized cashew nut shell oil and rubber.

A still further object of my invention is to provide such a contact surface comprising in addition to the polymerized cashew nut shelloil and rubber, one or more other materials such as a vulcanizer, accelerator, loader, filler and other materials as hereinafter described.

To the above and other ends which will hereinafter appear, my invention consists in a platen, feed roller or the like for typewriting and like machines as set forth in the following description and particularly pointed out in the appended claims.

In the drawing, wherein like reference characters designate corresponding parts in the different views:

Fig. 1 is a front elevational view, with parts broken away, of a platen in which my invention has been embodied;

Fig. 2 is an enlarged end elevational view, partly in section, of the platen shown in Fig. 1; and

Fig. 3 is an" enlarged end elevational view partly in section of another form ofplaten construction in which my invention has been embodied.

My invention is directed more particularly to platens for typewriting and like machines, but also is directed to feed rollers for such machines and when I use the term feed rollers herein I mean said term to be sufliciently comprehensive to include platens, as well as the feed rollers which coact with the platen to aid in feeding the paper.

It is desirable to have the platens and/or feed rollers for typewriting and like machines possessed of particular and exact physical properties in order to produce best results when in use, and which properties the usual rubber covered platens and feed rollers do not possess to a satisfactory degree. For example, it is desirable to provide a composition platen or feed roller covering which is capable of successful use in typewriting and like machines, and which will not deteriorate and become less effective with age, due to a hardening of the surface as time progresses; to a pitting of the surface of the platen from incessant impacts of the types thereon; to a polishing of the contact surface of the platen or feed roller that results in decreasing its feeding quality; to the application of heat, moisture, oil, petroleum products, or the like. The effect of age and use on the ordinary rubber covered platen and feed roller is to cause them to become hard and lose their resiliency. The impact of the types on the platen results in time in pitting the surface thereof, thereby rendering it less effective for the production of clear imprints on both the original and carbon copies. Moreover, when either a typewriter platen or feed roller ages and hardens in this manner, the contact surface becomes unduly smooth and gripping and feeding qualities thereof are reduced with the result that paper fed between such rollers will slip and feed improperly. In addition to this, however, the effect of age on a, typewriter platen tends to harden it and ren der the platen increasingly noisy, and the pitting.

is increased as the hardness of the platen increases.

I have discovered that by using polymerized cashew nut shell oil in a composition for the alone gives better writing qualities and more clearly defined imprints on both the original and carbon copies, but which will stand up much longer in use on the machine and will not become pitted and marred by the action of the types thereon. It has been found by experiment that with a' platen made in accordance with my present invention a soft platen of 85 density will produce better copies ,,than an ordinary rubber covered platen of 100 density, the platens and machines being the same except for the composition employed for covering the platen.

Cashew nut shell oil, which comprises substances known as cardol and anacardic acid, is the oil found in the shell surrounding the kernel of the cashew nut and is possessed of certain properties which allow it to be used to advantage in the production of coverings, outer plies or impact surface for typewriter platens and also for feed rollers. For example, it has been found that in quantities ranging from the smallest to a great many times the amount of the oil itself, and

such solutions are permanent.

Cashew nut shell oil modifies, conditions and controls the changes and characteristics in rub- *ber. When the oil is intermixed with rubber it gives to the lattencertain desirable characteristics not hitherto present in rubber, and does this without detracting from its general usefulness or having any deleterious effects thereon. For example, the mixture can be worked in the same manner as ordinary rubber for molding and ouring under practically the same conditions as have been used for a long time for molding and vulcanizing rubber alone, and the time of vulcanization is comparable to the time required for the vulcanization of rubber under similar conditions.

A notable effect secured by modifying rubber with cashew nut shell oil is that insolubility of vulcanized rubber in petroleum is secured. The product is not m rely insoluble in petroleum, but

further, is not s ftened, disintegrated 'or otherwise deleteriously affected. This becomes a faccashew nut shell oil imparts to rubber, or whichis present in the composition of cashew nut shell oil and rubber, is that of resistance to heat. It

. is well know that rubber ages, and breaks down when subjected to heat for some time, even at ordinary temperatures or temperatures below that at which rubber fuses or depolyrnerizes.

When, however, cashew nut shell oil is intermixed with rubber its age and resistance to the deleterious effect of heat is greatly increased.

Ordinary rubber which deteriorates in a given 'time, when intermixed with cashew nut shell oil remains alive and fresh for an indeterminate period .of time.

An example of a composition which I have found desirable for the above mentioned uses in platens and feed rollers for typewriting and like machines, and which possesses all of the advantages set forth above, may contain the following ingredients:

18% smoked sheet white crepe fine para rubber 35 cashew nut shell oil polymerized 18% blanc fixe 18% zinc oxide 2 lime 4% sulphur 5 carbon black The smoked sheet white crepe fine para rubber, listed above is the type of rubber used in my composition and performs the function of binding or holding the compounded parts of the composition together in the finished product. This rubber however, is only one example of many different suitable types of resilient binders or colloidal materials such as rubber that might be used in my composition and will retain their resiliency when compounded as hereinafter described.

Cashew nut shell oil, which is used in my composition in .the polymerized state, is polymerized by the addition of sulphuric acid and the application of heat. I This product is known on the market as Cardolite and is obtained by me as a solid substance that is soft and pliable like a piece of rubber. The cashew nut shell oilpolymerized imparts to the mixture the, characteristics and effects above set forth.

Blane fixe and zinc oxide are in the present instance, used as fillers to cut the cost of the finished product. Whiting or talc could be used in place' of the blanc fixe, but the latter is ground finer and. makes a better texture in the finished product.

Lime, the fifth item listed above, is used as a heat agent to generate heat when the mixture or compound is under vulcanization. This element also controls the'moisture in the other ingredients.

Sulphur, as is well known, is used to vulcanize the rubber and polymerized cashew nut shell oil in the ordinary manner.

Carbon black is used merely to color the finished product, and any other suitable coloring agent could be used equally well if desired.

The processof mixing and treating the above described compound or composition is the same as the ordinary process employed for preparing rubber coverings for platens in which polymerized cashew nut shell oil is not used, and as pointed out above the time of vulcanization is comparable to the time required for the vulcanization of rubber under similar conditions. The rubber is masticated on a standard two roll rubber mixing mill until soft. Then'all the mineral ingredients and the polymerized cashew nut shell specific composition embodying my invention it is to be understood that various changes may be made in the process, the several steps thereof, or the amounts and character of the various elements used, without modifying or changing the essential features andcharacteristics of the product produced.

I shall now describe two specific embodiments of my invention in platens for typewriting and like machines as they are disclosed in the accompanying drawing.

In Figs. 1 and 2, I have shown my invention applied to a typewriter platen of the so-called "cushion" type as disclosed in my Patent No. 1,671,763 dated May 29, 1928. According to this form of construction'in which my invention has been embodied, the platen, which is designated as a whole by the reference numeral Ill, comprises an inner core member ll, made of wood or any other suitable material, and a pair of platen heads l2. These platen heads, which have trunnions or bosses l3 constituting bearings for a platen shaft (not shown), are secured to the core H with the aid of screws 14. Mounted on the core H is a platen cover, designated as'a whole by the reference numeral l5, and made up of two concentric layers or plies of material, an outer layer or cover l6 and an inner layer or backing IT. The

outer layer or contact surface I6 is of my above described composition comprising rubber and polymerized cashew nut shell oil. The inside layer I], which acts as a backing for the outer layer is made of any suitable sound deadening material such as sponge rubber or ground felt having a small quantity of rubber suflicient to permit vulcanizing.

In making this type of platen, the backing ll may first be made up in the form of sheet material which is cut to the proper width, then brought around a mandrel and neatly spliced, or if desired this inside layer 'may'first be run onto the tubular form. There is next applied one ply of cloth or textile fabric l8 to the outside of the backing or inside layer II. This cloth or textile fabric is preferably frictioned or impregnated with a coating of rubber so that the parts may be properly united. On the outside of this fabric l8 there is applied a strip or tubing of unvulcanized rubber and polymerized cashew nut shell oil embodied in a composition as described above, which, when vulcanized, will produce the improved writing or contact surface for the platen. The platen cover I5 is then vulcanized in the usual manner, the mandrel removed, the platen cut to size and ground to provide an even and true surface and it is then mounted upon the core ll. After the platen cover has been mounted and fixed in the usual manner upon the core II the platen heads l2 are secured thereto.

In Fig. 3 I have shown my invention embodied in a so-called single wall platen which is designated as a whole by the reference numeral 20. This single wall platen comprises a core 2|, which may be made of metal, platen heads 22 having trunnions or bosses 23, and a cover 24. In the present instance the cover 24 comprises a layer of textile fabric and an outer layer of my im proved composition comprising polymerized cashew nut shell oil and rubber, said cover member 24 being formed in the same manner as described above for the platen' cover l5 shown in Figs. 1 and 2 with the first step of that process omitted. That is, the rubberized fabric is applied directly to the mandrel and the composition including polymerized cashew' nut shell oil is applied thereto. The cover is then vulcanized in the usual manner, the mandrel removed and the platen cut to size and ground to provide a true contact surface, said cover then being fitted upon the core 2|.

platen, and one which affords greater utility to the platens and feed rollers of typewriting and like machines generally and enables a better quality of' imprints to be produced by the use of such platens.

Although I have described in detail one specificcomposition embodying my invention and shown and described two different types of platens in which it may be embodied, it is nevertheless to be understood that various changes may be made therein and certain features or elements may be employed without others depending on the results desired, without departing from my invene tion as it is defined in the accompanying claims.

What I claim as new and desire to secure by Letters Patent is:

l. A platen for typewriting and like machines havinga contact surface comprising cashew nut shell oil.

2. A platen for typewriting and like machines comprising a layer of textile fabric and a layer of a composition including cashew nut shell oil.

3. A platen for typewriting and like machines comprising a cushion layer, a layer of fabric, and an outside working layer or contact surface of a composition including cashew nut shell oil.

4. A platen for typewriting and like machines having a contact surface made from a composition including polymerized nut shell oil.

5. A feed roller for typewriting and like machines having a contact surface made from a composition including rubber and polymerized cashew nut shell oil.

6. A platen for typewriting and like machines comprising a cylindrical core member and an outer cover of a composition including substantially 35% polymerized cashew nut shell oil and substantially 18% rubber.

7. A feed roller for typewriting and like machines comprising a layer of rubber coated fabric, and a contact layer of a composition including rubber andpolymerized cashew nut shell oil, said layers being vulcanized.

8. A feed roller for typewriting and like machines having a contact surface comprising a composition including polymerized cashew nut shell oil, rubber, sulphur, and a filler.

9. A feed roller for typewriting and like machines having a contact surface comprising polymerized cashew nut shell oil, 36% filler, and a vulcanizer.

10. A feed roller for typewriting and like machines having a contact surface comprising polymerized cashew nut shell oil, rubber, blanc fixe, zinc oxide, and sulphur.

11.. A feed roller for typewriting and like machines having a contact surface comprising polymerized cashew nut shell oil, rubber, blanc fixe, zinc oxide, sulphur and carbon black.

12. A feed roller for typewriting and like machines having a contact surface comprising polymerized cashew nut shell oil, a suitable resilient binder, a filler anda vulcanizer.

13. A feed roller for typewriting and like machines having a contact surface comprising 35% polymerized cashew nut shell oil.

14. A feed roller for typewriting and like machines having a contact surface comprising 35% 5 polymerized cashew nut shell oil and 18% smoked sheet white crepe fine para rubber.

15. A feed roller for typewriting and like machines having a contact surface comprising 35% polymerized cashew nut shell oil, 18% smoked sheet white crepe fine para rubber, 18% blanc fixe, 18% zinc oxide, 2% lime, 4% sulphur, and. 5% carbon black.

CHARLES T. DICKEY. 

